As you can see, simply using a select statement
as done above produces the same list of values in the array. A criterion is
a condition applied to a set of values to find out which one(s) respond(s)
to the condition or validate the condition. When applied to a list, a
criterion examines each member, finds out what member responds to it, if so,
adds that member to the from list.

To apply a criterion, you create a Boolean operation
between the in statement and the select statement. This
criterion is actually formulated using the where operator. The
formula to use is:

Of course, the purpose of querying a list is to isolate
one or more values. As such, you can create an expression that checks a
value and applies some condition to it. For example, in this list of
numbers, you may want to find out whether it contains one or more numbers
that are divisible by 5. This operation can be carried by the % operator as
in "number % 5"; but number % 5 is pure algebra, not Boolean. Therefore, you
must add a condition to make it a valid Boolean expression. For example, you
can find out if the number % 5 operation is equal to 0. Here is an example:

You can create a criterion that works perfectly but
rather want its opposite. To get it, you can negate the expression. To do
this, you use the ! operator of the C# language. To make the expression easy
to read, you should include it in parentheses. That is, put the ! operator
in the beginning of the logical expression followed by parentheses that
include the actual logical expression. Here is an example: